Spark distributor



April 1961 E. R. LARGES 2,977,946

SPARK DISTRIBUTOR Filed July 18, 1955 FIG.3.

no as 2 L y UL] 5 2 g} INVENTOR.

ERNEST R. LARGES r/! I W ATTORN 5 I SPARK DISTRIBUTOR Ernest R. Larges',-Detroit, Mich., assignor to Holley Carburetor Company, Detroit, Mich, a corporation,

- of Michigan Filed Jnly 18, 19ss,sei-. N6. 522,791

16 Claims. or. 123-117 The present invention relates to a spark distributor and moreparticularly, to novel ignition timerstructure.

] It is an object of the presentinvention to provide ignition timer structure including means responsive to speed and means responsive to variable pressure, said means beingindependently adjustable, and single actuating means operably connected to both of said speed and variable pressure responsive means.

"More specifically, it is an object of the present invert-- Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with' the accompanying drawings, wherein:

Figure 1 is a plan view of the spark control portion of a distributor. V

Figure 2 is a partial sectional view taken on the line 2-2, Figure 1. V

Figure 3 is a sectional view taken on the broken sectional line 3-3, Figure 2.

Figure 4 is also an enlarged fragmentary sectional view taken on the line 22, Figure 1.

Figure 5 is a plan view of an actuating plate.

Figure 6 is an end elevation of theplate shown in Figure 5. t

Figure 7 is a fragmentary vertical sectional view on the line.77, Figure 3.

The structural illustrated in the figures is a portion of a distributor with the cover removed; It will be understood that the cover includes the usual rotor operatively connected to the illustrated structure for rotation thereby.

The structure comprises a housing 10 including a depending reduced portion 12 having an opening 14 therethrough for the reception of a driving shaft 16. The upper end of the cup-shaped housing 10 is closed by a plate 18 on which is mounted the pivoted breaker arm 20 including a cam engaging portion 22 engageable by the rotating cam 24 to effect make and break of the circuit at the contacts indicated at 26. The cam 24 is fixedly securedto a tubular shaft 28 which is rotatable with the shaft 16 in its normal rotation,but which is also angularly adjustable relative thereto to advance or retard the spark.

The present invention relates to means interconnecting the driving shaft 16 and the driven tubular shaft 28 carrying the cam 24 to advance or retard the spark as required for efficient engine operation.

It isrequired to advance or retard the spark in known manner in accordance with variable conditions, the usual conditions employed to effect spark adjustment being engine speed and manifold vacuum. It is desirable to provide means responsive to these two variable conditions which are independently adjustable or calibrated and ,4 2,977,946 1C6 we n Pa ent d Apr. 4, 1961.

V which produce independent or arithmetically additive or subtractive results. In accordance with the present invention this is accomplished in a simple and efficient manner by providing fluid pressure responsive mechanism carried directly by radially movable centrifugal weights, the fluid pressure responsive mechanism including an element movable radially of .the axis of rotation so that such element is movable radially an amount precisely equal to radial movement of the centrifugal weight in response to variations in speed and is'additionally movable radially of the axis of rotation an amount directly dependent upon changes in fiuid pressure.

.To accomplishthe foregoing a pair'of devices indicated generally at 30 are provided, these elements being identical in construction and provided in diametrically opposite relationship to each other to effect dynamic balance The devices each comprise a housing 32 open at its radially inner end and having a reduced radially outwardly extending portion 34 provided with an enlarged opening 36. As best indicated in Figure 3, the housings 32have edge flanges 37 connected to'four arms or posts 38 extending upwardly from a support plate 40, the connection being byscrews 42 and spacer sleeves 44.

Slidably movable within the housing 32 is a centrifugal weight 46 having an enlarged portion 48 movable in the main portion of the housing 32 and a reduced portion 50 movable in the reduced portion 34 of the housing. Intermediate the enlarged portion 48 and the reduced portion 50 is a shoulder 52 which forms a seat for a conical compression spring 54, the other end of which seats against the shoulder 56 provided between the main portion of the housing and the reduced portion 34 thereof.

The centrifugal weight 46 has extending therethrough in a direction radial of the shaft 16 an enlarged opening 60 which is closed at the radially outer end by an adjustable threaded plug 62. for a second conically formed compression spring 64 and is accessible through the opening 36 at the radially outer end of the housing for adjustment so that the effectiveness of the spring balance means for the centrifugal weight may be readily adjusted or calibrated.

The threaded plug 62 in turn is provided with a threaded opening 66 receiving an adjusting screw 68 to the. inner end of which is connected a spring seat 70 which engages. one end of a compression spring 72. The

adjusting screws 68 are also accessible through the openings .36 so that the spring means opposing radial outward movement of the centrifugal weights and the spring means opposing radial outward movement of the diaphragms in response to an increase in manifold vacuum may be separately and independently adjusted. The threaded plug 62 closes the rear end of the enlarged opening and the radially inner end of this opening is closed and sealed by a flexible diaphragm 74. The spring 72 engages the diaphragm 74 and urges it radially inwardly. Adjacent the diaphragm 74 is a diaphragm and this in turn effects angular adjustment of the shaft 28 and hence the timing cam 24 relative to the drive shaft 16.

In order to effect angular adjustment of the plate 79 of thetadjusting arm about the axis of the shafts,

F each of the links 78 as bestseen in Figs. 3 and 7 includes The threaded plug forms a seat Arms , 3 an offset actuating arm 82 including an apertured portion 84 having an elongated aperture adapted to receive a pin 81 depending from the'radially extending adjusting arms 80.v Thus, the link 78 includes a first portion 86 which. is movable radially of the axis of the shafts, and an offset actuating arm which moves generally tangentially of a circle concentric with the axis of the shafts.

In order to obtain a response dependent upon variations in fluid pressure, the passage 14 includes a lateral enlargement 90 which receives a ring 92 in communication with the passage 94 connected by suitable means indicated at 96, which is adapted to be connected to the manifold 97. The drive shaft 16 has a radially extending passage 98 communicating with the axially extending passage 100 closed at its upper end by a plug 102. In

the horizontal plane passing through the centers of the housing 32 the drive shaft 16 is provided with radially outwardly extending tubes 104 which extend through an enlarged opening in the diaphragm covers 76 and extend through central openings in the diaphragms 74. As illustrated in the figures, the tubes extend substantially beyond the diaphragms where the latter are in their radially inward position, and hence not only connect the interiors of the chambers closed by the diaphragms with manifold vacuum, but also constitute guide means for the diaphragms.

The portion 86 of each of the links 78 is provided with a radially extending opening through which the tube 104 extends and the tubes thus constitute guide means for the links as well as the diaphragms.

Adjustable abutment means comprising a cam ring 110 is provided. The ring 110 is rotatably mounted on tubular shaft 28 against a shoulder 112, the ring being retained in adjusted position by a relatively tight frictional fit. The periphery of the ring constitutes an abutment engageablc by the diaphragm cover plate 76 so as to limit radially inward movement of the centrifugal weights 46. The ring 110 is provided with radially extending openings 114 by means of which the ring may be adjusted to the required position.

With the foregoing construction it will be apparent that the fluid pressure responsive means is adjustable as aunit, including the actuating element or link secured thereto, and such adjustment is effected in accordance with changes in centrifugal speed. The movement of the link 78 resulting from moveemnt of the diaphragm 74 is radial of the shafts and is of course parallel to the direction of movement of the centrifugal weight 46 resulting from changes in engine speed. Accordingly, the resultant cam adjustment is effected by a movement of a control element which in turn is the arithemetical sum or difference of movements effected independently of each other in response to changes in engine speed and manifold vacuum. Moreover, the movable member responsive to changes in centrifugal speed may be independently calibrated or adjusted as to the effectiveness of the counter-balance spring by adjustment of the threaded plug 62, and in like manner the action of the diaphragm in response to variation in manifold vacuum may be adjusted or calibrated independently by adjustment of the screws 68. The adjustment effected by rotation of the abutment member 110 determines. theinitial compression of spring 54.

The foregoing construction is characterized by its simplicity, its compactness, and by its highly desirable theory of operation which combines an adjustment responsive to two variables into a simple mechanical adjustment of a cam which is angularly adjustable relative to a driving shaft.

The drawings and the foregoing specification constitute a description of the improved spark distributor in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

l. Ignition timer structure for an internal combustion engine having a manifold, said structure comprising a driving member adapted to be connected to a rotating part of the engine, a driven member coaxial with said driving member, timing means carried by said driven member, a centrifugal element carried by one of said members for rotation therewith and for radial movement a with respect thereto, resilient means opposing outward radial movement of said element, a complete pressure responsive device carried as a unit by said centrifugal element and including a control element movable relative to said centrifugal element radially of the axes of said members, means adapted to connect said pressure responsive device to the engine manifold, a connection between said control element and the other of said members in position to effect angular adjustment between said members upon a change in engine speed or manifold vacuum.

2. Ignition timer structure for an internal combustion engine having a manifold, said structure comprising a driving member adapted to be connected to a rotating part of the engine, a driven member coaxial with said driving member, timing means carried by said driven member comprising a pair of inwardly facing cups carried by one of said members at diametrically opposite sides of the axes of said members, weighted elements movable in said cups radially of the axes of said members, complete pressure responsive devices carried as a unit by said weighted elements, said devices comprising control elements movable thereon in response to variations in pressure, means adapted to connect said pressure responsive devices to engine manifold vacuum, and means connecting said control elements to said other member.

3. Ignition timer structure for an internal combustion engine having a manifold, said structure comprising a driving member adapted to be connected to a rotating part of the engine, a driven member coaxial with said driving member, timing means carried by said driven member comprising a pair of inwardly facing cups carried by one of said members at diametrically opposite sides of the axes of said members, weighted elements movable in said cups radially of the axes of said members, pressure responsive devices carried by said weighted elements comprising control elements movable thereon in response to variations in pressure, means adapted to connect said pressure responsive devices to engine manifold vacuum, and means connecting said control element to said other member, said pressure responsive devices each comprising a recess at the radially inner end of each of said weighted elements and a sealed member movable in said recess to which said control element is connected.

4. Ignition timer structure responsive to speed and fluid pressure comprising a rotary drive shaft, a cam rotatable with said drive shaft and angularly adjustable about the axis of said shaft, a centrifugal weight, guide means connecting said weight to said shaft for rotation therewith and for radial movement relative thereto, a chamber movable with said weight, a diaphragm element closing said chamber and movable radially of the axis of said shaft, resilient means connected to said weight and opposing radial outward movement thereof, a link connecting said diaphragm element to said cam, said link having a portion extending radially of said shaft, and means including a passage in said shaft and an opening through said radial portion of said link adapted to connect the interior of said chamber to a source of variable pressure.

5. Ignition timer structure responsive to speed and fiuid pressure comprising a rotary drive shaft, a cam rotatable with said drive shaft and angularly adjustable about the axis of saidshaft, a centrifugal weight, guide means connecting said weight to said shaft for rotation therewith and for radial movement relative thereto, a chamber movable with said weight, a diaphragm element closing saidichamber. and. movable radially of the axis of said shaft, resilient means connected-to said Weight-and opposing radial outwardmovement thereof, said shaft having an axially'extending passage adapted to be connected toa source of variable-pressure, a radially extending tube connecting at one end to saidpassage' and having its other end extending through said diaphragm element into said chamber, and a link slidable on said tube and connecting said diaphragm element and cam.

'6. Ignitiontimer structure responsive to speed and fluid pressure comprising a rotary drive shaft, a cam rotatable with said drive shaft and angularly adjustable about the axis of said shaft,.a centrifugal weight, guide means connecting said weight to said shaft for rotation therewith and for radial movement relative thereto, a chamber movable with said weight, a diaphragm element closing said chamber and movable radially of the axis of said shaft, resilient means connected to said weight and opposing radial outward movement thereof, said shaft having an axially extending passage adapted to be connected to a source of variable pressure, a radially extending tube connecting at one end to said passage and having its other end extending through said diaphragm element into said chamber, a link slidable on said tube and connecting said diaphragm element and cam, said link having a tubular portion extending radially of said shaft receiving said tube, and an offset actuating arm providing the connection to said cam.

7. Ignition timer structure responsive to speed and fluid pressure comprising a rotary drive shaft, a cam rotatable with said drive shaft and angularly adjustable about the axis of said shaft, a centrifugal weight, a housing in which said weight is movable radially of said shaft, said weight having an enlarged opening extending therethrough radially of said shaft, a diaphragm closing the radially inner end of said opening. a member closing the radially outer end of said opening to form a closed chamber, means adapted to connect said chamber with a source of variable pressure, a spring in the radially outer end of said housing and engaging against said member, and means for adjusting said member radially of said opening to vary the effectiveness of said spring.

8. Ignition timer structure responsive to speed and fluid pressure comprising a rotary drive shaft, a cam rotatable with said drive shaft and angularly adjustable about the axis of said shaft, a centrifugal weight, a housing in which said weight is movable radially of said shaft, said weight having an enlarged opening extending therethrough radial- 1y of said shaft, a diaphragm closing the radially inner end of said opening, an annular threaded plug closing the radially outer end of said opening to form a closed chamber, means adapted to connect said chamber with a source of variable pressure, a spring in the radially outer end of said housing and engaging against said plug, means for adjusting said plug radially of said opening to vary the eifectivenessof said spring, an adjusting screw extending through said threaded plug into said chamber, a spring seat carried by said screw, and a compression spring extending between said spring seat and said diaphragm.

9. Ignition timer structure comprising a shaft, a cam operatively connected to said shaft for rotation thereby, adjusting means for effecting angular-adjustment of said cam relative to said shaft, said adjusting means compr sing first means responsive'solely to variation in fluid pressure including an element connected to said cam for adjusting it angularly of said shaft, and second means responsive solely to shaft speed for adjusting said pressure responsive means in its entirety.

10. Ignition timer structure comprising a shaft, a cam operatively connected to said shaft'for rotation thereby, adjusting means for effecting angular adjustment of said cam relative to said shaft, said adjusting means comprising a centrifugal weight connected to said shaft for movement radially thereof upon changes in shaft speed, a device responsive solely to variations in fluid pressure to said element.

11. Ignition timer structure forv an internal combustion engine having a fluid pressure source variable in ac-' cordance with engine operation, said structure comprising a shaft adapted to be driven at a speed dependent on engine speed, a timing cam on said shaft rotatable therewith and capable of limited angular adjustment relative thereto, guide means carried by said shaft and extending diametrically oppositely therefrom, centrifugal weights movable on said guide means radially of said shaft, resilient means opposing outward movement of said weights, operating means fixed to said cam and including portions extending diametrically oppositely from said shaft at approximate right angles to said guide means, and connecting means responsive solely to variations in pressure of the pressure source and including laterally offset arms connecting said weights to said portions of said operating means.

12. Structure as defined in claim 11 in which said connecting means includes pressure responsive means adapted to be connected to the variable fluid pressure source.

13. Structure as defined in claim 11 in which the connecting means comprises an expansible and contractable chamber having a movable wall adapted to be connected to the source of variable fluid pressure, and resilient means separate from the first mentioned resilient means operatively connected to said movable wall.

14. In an ignition distributor for an internal combustion engine having an induction passage, a drive shaft adapted to be driven in accordance with engine speed, a cam member coaxial with said shaft and adapted to be angularly adjustable relative thereto, means responsive to changes of engine conditions for adjusting said cam member relative to said shaft, said means combining speed responsive elements and pressure responsive elements, said speed responsive elements being capable of independently adjusting said cam in response to variations in engine speed, and said pressure responsive elements being so arranged for relative movement on said speed responsive elements and being capable of independently adjusting said cam in response to variations in induction passage vacuum regardless of engine speed and without moving said speed responsive elements.

15. In an ignition distributor for an internal combustion engine having an induction passage, a drive shaft adapted to be driven in accordance with engine speed, a cam member coaxial with said shaft and adapted to be angularly adjustable relative thereto, means responsive to changes of engine conditions for adjusting said cam member relative to said shaft, said means combining speed responsive elements and pressure responsive elements, said speed responsive elements being movable to a position dependent only on engine speed and capable of independently adjusting said cam in response to variations in engine speed, and said pressure responsive elements being mounted for relative movement on said speed responsive elements and movable thereon for independently adjusting said cam in responsive to variations in induction passage vacuum regardless of engine speed and without moving said speed responsive elements.

16. Ignition timer structure comprising a rotary shaft, a centrifugal weight, guide means connecting said weight to said shaft for radial movement with respect to said shaft, spring means opposing outward movement of said weight, a pressure responsive device comprising a fluid pressure chamber connected to said weight for movement therewith radially of said shaft, said chamber having a wall movable relative to said chamber also in a direction radially of said shaft, spring means opposing movement of said wall relative to said chamber, a timer cam mounted on said shaft for angular adjustment relative thereto, and drive and adjusting means connecting said movable Wall to said cam for driving said cam at shaft speed and for adjusting said cam relative to said shaft in accordance with fluid pressure in said chamber and shaft speed.

References Cited'in the file of this patent UNITED STATES PATENTS Chryst Feb. 10, 1931 Hittle June 2, 1931 Arthur Jan. 24, 1933 Mallory Feb. 18, 1947 Hartman et a1. Dec. 28, 1954 Johnson Oct. 16, 1956 

